Non-aqueous batteries such as lithium secondary batteries are being turned into practical use in a variety of applications ranging from consumer power sources for, e.g., cell phones and notebook computers to drive power sources equipped on vehicles such as automobiles. Important properties required for non-aqueous batteries such as lithium secondary batteries may include high discharge capacity and stable charge-discharge cycle. The stable charge-discharge cycle herein means that the discharge capacity of the non-aqueous battery does not easily decrease even after repeated charging and discharging. Further, such an excellent stability of charge-discharge cycle may be also referred to as excellent cycle property.
It has been conventionally known that the composition of the non-aqueous electrolyte solution has a significant influence on the stability of the charge-discharge cycle of the non-aqueous batteries such as lithium secondary batteries. Therefore, there has been proposed a technology for improving performance of a non-aqueous battery by developing the composition of the non-aqueous electrolyte solution. For example, Patent Literature 1 proposes an electrolyte solution in which lithium trifluoromethanesulfonate is dissolved as an electrolyte in a mixed solvent containing specific amounts of a cyclic carbonate ester, a chain carbonate ester, and an ether. Further, Patent Literature 2 proposes a non-aqueous battery in which a metal composite oxide having a high discharge capacity is used as a negative electrode and a mixed solvent of, e.g., ethylene carbonate and a chain carbonate ester is used as a non-aqueous electrolyte. Patent Literatures 3 and 4 describe technologies of adding a simple cyclic ether compound such as 1,3-dioxolane, tetrahydrofuran, tetrahydropyran, and dioxane to a non-aqueous electrolyte solution.